Arabica vs Robusta Coffee: What’s the Difference?

There is one coffee bean which is considered the queen of beans: it dominates the world’s coffee production and rules the specialty market. People don’t just swear by its superior quality, they “believe” in the pureness of its complex, sweet and acidic bouquet. They show it off in its untainted state everywhere they can: “100% Arabica!”, they invoke with one fist in the air.

And then there’s Robusta. Such a dirty, blasphemous word. Critics often describe it as tasting of burnt rubber. Definitely not sexy advertising. An Arabica and Robusta blend? Sacrilege!

Yet, it’s the second most traded kind of coffee in the world.

Is Arabica really better than Robusta?

The short answer is: yes and no. Like wine, the kind of grape or, in this case, the type of beans, each with different chemical features and qualities, does affect the ultimate flavour profiles. Bare with me and we’ll have a look at these specific characteristics in a moment.

But keep this in mind:

the quality and the complexity are very much influenced by a number of factors: the particular variety of the plant, its husbandry, harvesting, processing and roasting. The care and attention taken during each of these steps is what turns a mundane beverage into a rich and unique experience.

What are Arabica and Robusta?

With over 120 species of coffee discovered around the globe, only two are really likely to show up in your cup of morning brew: Coffea arabica, or simply Arabica, and Coffea canephora, aka Robusta. They might look quite similar at a first glance.

Don’t let this fool you!

There are many botanical and chemical differences between the two, giving them distinctive tastes: the one sweeter and fruitier, the other nuttier and full bodied with a higher caffeine content. Stick with me as we take a closer look at the eternal debate: Arabica vs Robusta, which one is better?

For starters, they occupy 60% and 35-40% of the world coffee trade respectively. Other species in East Africa and Madagascar are sometimes used locally to make coffee on a very small scale. So, what are the main differences between Arabica and Robusta?

Let’s jump right in!

Origins and Distribution

Even though Robusta has long been considered Arabica’s ugly sister, recent research suggest that, in fact, it is not. It turns out that Robusta is actually its parent! By sequencing its genes, scientists have discovered that, somewhere in southern Sudan, Robusta crossed with another species called Coffea euginoides giving birth to a new hybrid: Arabica.

Nevertheless, Arabica was probably the first to be consumed —at the beginning in its wild varieties flourishing in the shady rainforests of Ethiopia— and then farmed. Cultivations quickly crossed the narrow Red Sea to their Arabian neighbours who tried to monopolise the coffee trade.

And guess what? It didn’t work.

As the stimulating drink became more and more popular, seed and plant smugglers could not be stopped, and coffee farming took over the plains and mountainsides of the equatorial region between the Tropic of Cancer and the Tropic of Capricorn, now known as the Coffee Belt.

So what about now?

Today, although many countries grow both species, most of the world’s Robusta is found in Central and Western Africa, parts of Southeast Asia, especially India, Indonesia and Vietnam, while Arabica is mainly grown in East Africa, Central and South America.

The Coffee Plant

The coffee plant is an evergreen which grows as a shrub or a tree, sometimes pruned to about 1.5 m (5 ft) high.

Why is that? Let me explain.

The cherries on a branch mature at different times so hand-picking is still the best way to collect to the plump red cherries without including the unripe ones which would spoil the batch. Unless you use harvesting machines or a team of giant farmers, you better prune those trees!

So, what are the differences between the Robusta and Arabica trees?

The Robusta tree is usually bigger than its Arabica counterpart: it can reach up 10-12 m (33-40 ft) in height against 3-4 m (10-14 ft) of the latter. But that’s not all.

It also has double the yield of Arabica which will produce around 1-5 kg (2 -11lb) of cherries per season, if well cared for, making Arabica more expensive to grow… with some unpredictable consequences. But I’m jumping ahead of myself. We’ll talk more about that later.

And lastly, Arabica’s cherries are generally larger and more elongated than Robusta’s and its beans have a characteristic curved crease in the middle.

Climate and Environment

First of all, coffee plants like mild, humid climates and are sensitive to rapid temperature changes. They are extremely susceptible to frost which might only do some damage to the year’s production or…it could kill off entire plantations!

For instance, in 1975, during the Brazilian “black frost”, more than 200 million coffee trees were affected by the five days of subfreezing temperatures, which sent coffee prices skyrocketing around the world.

Then, where do Arabica and Robusta grow?

They are mainly found around the equator and in Tropical and Subtropical areas. Specifically, the heartier Robusta can grow in the lowlands up to 900 m (3000 ft) above sea level where the temperatures are warmer at about 20-30 °C (70-85 °F).

By contrast, the more delicate Arabica thrives on the mountainsides at higher altitudes 900-2000 m (3000-6600 ft) above sea level, where the climate is more temperate, though optimal altitude varies with proximity to the equator. Beyond that, rainfall patterns determine flowering periods but intense rains or droughts can damage the flowers and cherries.

Usually, Arabica grows in regions with distinctive wet seasons, and consequently, flowering times are quite predictable and sometimes happen even twice a year!

But, how much water does it drink up?

It needs between 1500 and 2000 mm (60-100 in) of rainfall annually and its deep roots allow it to survive when the most superficial soil is dry. The cherry ripens 9 months after flowering. On the other hand, Robustas cherries take longer to mature, around 10-11 months. They are cultivated in areas where the weather is unstable and require frequent and heavier rains, 2000-3000 mm (80-120 in) a year.

Chemistry and Flavour

Let’s begin by saying that the chemical components in the beans, such as oils, sugars and acids, are tightly linked with the particular flavour profile of a coffee.

For example, Arabica generally contains a higher number of oils (15-17%) and sugars (6-9%) than Robusta, making for a sweeter cup with more complex aromas and a smooth and supple texture.

But there is more!

The sugars in the bean also break down when roasted creating compounds that lend acidic notes to the coffee, even though Arabica actually contains less acids than Robusta.

However, Robusta’s low oil content (10-12%) generally gives a longer and more stable crema when pulling a shot of Espresso. You know that lustful, golden, tanned froth on top of an Espresso? Well, it is made of tiny air bubbles where many of the oils are suspended. But, too much fat actually destroys the foam!

Robustas definitely taste more bitter and “hard” than Arabicas. Why is that?

Robustas have a lower sugar content (3-7%) and double the amount of caffeine (1.7-4%) and Chlorogenic Acids (CGAs).

Does this mean that Arabica is a better quality bean? Not at all! It makes Robusta great if you’re looking for a bit of an extra kick in the morning or if you like cappuccinos, as its stronger taste still manages to shine through the milk.

And the really cool thing is:

Robusta’s high caffeine and CGAs content makes it more resistant to diseases, pests and fungi which proliferate in hot, wet climates, such as leaf rust and the coffee berry disease. So, the sturdiness of this species means that overall it is easier and cheaper to cultivate than Arabica.

Why does Robusta have such a bad rep?

Here’s the rub:

while Arabica has many different commercial uses, from lesser-quality to Specialty coffees, Robusta has always been considered as belonging to the low-end category of the market. In fact, its price is half that of Arabica and it is mostly used for instant, soluble or cheap coffees.

Although, in Italy, it has been traditionally blended with Arabicas for its stable and thick crema in Espresso, Robusta was also used to reduce the price of blends during and after war time…not always manifestly.

As we’ve already seen, its hardier nature makes it less expensive to produce. Believe it or not, sometimes the market might want an inferior quality product to keep it cheap.

Remarkably, the concept of Specialty coffee was born out of its distancing from the harsher, bitter and sometimes straight-out awful taste of Robusta: “100% Arabica” was the new claim!

Think about this for a moment:

Arabicas and Robustas prices are set in reference to two different markets: the NYSE in New York and the LIFFE in London. But did you know that a LIFFE Robusta contract allows approximately 450 defects for a 500g sample? That is approximately 10 times the number of defects allowable in a commodity Arabica ‘C’ contract!

Put it this way:

a lot of the bad taste in Robusta is not inherent in the bean, but mainly due to the high presence of black beans and sour beans and all kinds of other defects! In addition to this, there were no cupping protocols for Fine Robustas or premiums for high-quality lots.

The bottom line is:

with no incentives, why would farmers invest money, time and effort into attentive harvesting and processing?

It is only in the last decade or so that governments and international organisations have taken an interest in researching the unique properties of this species and have created specific cupping protocols.

What did they find?

Perhaps unsurprisingly, they have discovered that taste improves when each stage of the bean evolution receives the same care as the Arabica bean. In particular, they found that plant variety, cultivating at higher altitudes, hand picking, wet or honey processing, all contribute to developing sweeter, fuller and more complex tastes.

Farmers are already experimenting and producing high quality Robustas and even 100% Robustas which have a market in Korea.

For example, in India, where there is a long tradition of Robusta cultivations, Sethuraman Estate’s Robusta Kaapi Royale (RKR) has become the first Robusta coffee certified by the Coffee Quality Institute’s R Coffee™ System in 2012.

In fact, we actually use Indian Robustas in some of our own Espresso blends: a washed wild Robusta from the Nilgiri Biosphere Reserve for our Fusion and an India Kaapi Royal for our Cool.

A blend of Arabica and Robusta can constitute a great choice to taste a whole range of flavours, each bean bringing out its own characteristics and advantages, reducing the acidity of the Arabica or the hardness of the Robusta, offering body and sweetness, in a way that a single origin might not.

So what does it all come down to?

We’ve seen how each bean and plant has unique characteristics which need to be considered individually. You wouldn’t just say, point blank, that red wine is better than white, would you?

We’ve also seen how Robusta’s hardiness might have been its downfall for a while, creating a vicious cycle of lower standards and bad reputation.

But things are changing.

So, is Arabica better than Robusta? Not inherently. The market might still consider it of superior quality and treat it as such, but Robusta is full of barely discovered potential.

It all adds up to this:

go and try different coffees. Don’t just think in terms of Arabica vs Robusta. Ask about how they are cultivated and processed. Experiment with single origins and blends and find what works best for you.